It is believed this artifact is a 37 kW (50 hp) Curtiss E-4, Serial Number 1, operated at a lower than normal rotational speed. It was the first of Curtiss water-cooled engines, and the second of two engines to power the U.S. Army Signal Corps Dirigible No. 1, the first U.S. military airship. The engine drove a tubular steel shaft about 6.7 m (22 ft) long on which was mounted a wooden propeller designed by Lt. Thomas E. Selfridge.
In 1908, the Signal Corps awarded Thomas Baldwin a contract for the construction of the airship not to exceed 36.6 m (120 ft), to be completely maneuverable, and to obtain a speed of 32 km/hr (20 mph). Baldwin piloted the airship, and Glenn Curtiss was the engineer. In the official speed run, the Baldwin airship reached 31.38 km/hr (19.61 mph).
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.
1908
United States of America
PROPULSION-Reciprocating & Rotary
Curtiss Aeroplane and Motor Company
Type: Reciprocating, 4 cylinders, water cooled, in-line type
Power rating: 14.9 kW (20 hp) at 450 rpm
Displacement: 6.44 L (393 cu in)
Bore and Stroke: 127 mm (5 in) x 127 mm (5 in)
Weight: 114 kg (250 lb)
A19280012000
Gift of Mr. Gould Dietz
National Air and Space Museum
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